Improvement in bridges



UNITED STATES PATENT OEEICE.

JAMES S. YERK AND GEORGE H. HEMING, OF TIFFIN, OHIO.

IMPROVEMENT IN BRIDGES.

Specication forming part of Letters Patent No. 34,023, dated December 2t, 1861.

To all whom t may concern:

Be it known that we, JAMES S. YEEK and GEORGE H. HEMING, both of the city of Tifiin, in the county of Seneca and State of Ohio, have invented certain new and useful Improvements in the Truss-Frame of Bridges and Arches, which may also be applied to railings-and fences and wherever the trussframe is used; and We do hereby declare that the following is a description thereof in terms which we now conceive to be sufficiently full and exact, reference being had to the annexed drawings, making a part of this speciiication, in which- Figure l is a side elevation of a bridge; Fig. 2, an enlarged elevation of section A and half of B of Fig. l; Fig. 3, a vertical section through the line c f Fig. 2; Fig. 4, a side ele- Vation, enlarged, of the end post D of Fig. l; Fig. 5, a side elevation of the inner half of end post D; Fig. 6, a top view'of upper chord in Fig. 2; and Fig. 7 a perspective view of the inner halves of sections A and B of Figs. l and 2, showing the joints by means of which the respective panels are united.

The nature of our invention consists, first, in the employment in truss-frames of metallic tubes bisected longitudinally; second, in casting each of the longitudinally-bisected sections of the panels of a truss-frame in a single piece, embracing a longitudinal half of the cross-braces and upper chord and a portion of the shoe or heel-post, and, third, in the peculiar manner in Which the shoes or heel-posts are formed and the panels united.

To enable others skilled in the art to make and use our invention, we will proceed to describe its construction and operation.

Each panel, as A and B, Figs. 1, 2, and 7, of our truss-frame, including the upper chord and cross-braces, is formed of half-tubes a and IJ, Fig. 3, which when put together form tubes, as represented at c d of the same gure, the line e showing the point of bisection. Each longitudinal section of each panel is also composed of one-half the upper cord and crossbraces and a portion of the shoes or heelposts, as represented at Fig. 7, where two of the inner sections of panels are shown, and is a single casting. The construction of these shoes or heel-posts and the method of uniting the contiguous sectional panels are as follows: As before said, Fig. 7 represents the inner sections of two adjoining panels. s f a a. g g a ct" and g and g show the longitudinally-bisected tubes, and these, together with the extremities t I) b p and o p b u, the single casting of half-tubed upper chord, crossbraces, and portions of shoes or heel-posts. Now, taking the section A of Fig. 7, it Will be observed that the extremities Z and p are notched or halved from the outer surface, leaving kerfs partly bounded by lines w 'm 3 and c c. The extremities o and b of the section B are similarly notched or halved from their inner surface, leaving a tongue or tenon, which respectively t into the kerfs Z p. From this construction it will be seen that if either section is subject to vertical strain either up or down it will be resisted by the other, the shoulders c and c of the section A interlocking with the shoulders d and that corresponding with c of the section B and the shoulders m and 2 of the former interlockin g with the shoulders e and that corresponding with ,e of thelatter. This constitutes a mitered lap-joint and furnishes in itself that part of the shoe or heel-post apper` tainm g to the inner section of a panel. The outer sections are formed in the same manner, and when the two are put together and any two panels joined the joints and shoe or heel-posts on the lower ends of the cross braces form themselves into a single tenon, as seen at E, Fig. 2, which is received into a mortise formed on the lower chord, Whichis made of plates of wronght-iron. In this position the sections and the panels are bolted together and to the lower chord, as seen at f f and f f, Fig. 2, and the whole is strengthened by means of king-bolts 71, h', Fig. l. The end posts D, Fig. et, are also formed of longitudinally-bisected tubes, as seen at Fig. 5, and are attached to these panels in the same manner that panel is attached to panel.

By the use of bisected tubes in the construction of trusswvorkwe not only secure the strength of tubes, but a ready and cheap means of connecting the tubes together. By casting longitudinal sections of panels together, including parts of the upper chord, cross-braces, and shoes or heel-blocks, we are able to dispense With a large number of bolts and a great amount of labor, and by our frames in longitudinal sections, each section embracing half of the upper chord and crossbraces and a, portion of the shoe or heel-post, as set forth.

3. The manner above described of connecting the sections of one panel to those of another in truss-frames Where the said connection embraces within themselves the shoes or heel-posts, as stated.

In testimony whereof We have hereunto set our hands this 25th day of November, A. D.

JAMES S. YERK. G. I-I. HEMIN G. In presence of- H. A. TAGGART, JOHN HHRER. 

